Fluid connections in food and pharmaceutical industries are commonly made with flanged connectors clamped to each other. The connectors have hollow spigots to which tubing is connected in a fluid-tight manner. The flanged connectors can be made to tight tolerances, as can seals between two flanges, whereby there is little scope for stagnant accumulation at the flanges per se of material which can become contaminated, for instance by bacteria, and hence cause a hazard.
However the connection between the hollow spigot and the tubing can provide a stagnant region and a potential hazard. This arises because the nose of the connector's spigot is tapered where it meets the tube. The latter is close to its free diameter at the small diameter end of the spigot and there is little resistance to pressurised fluid permeating between the spigot and the tube. The pressure of the fluid is liable to force the fluid right up the taper and cause a leak or at least leave a residue of the fluid between the tube and the taper.